Many mechanisms, such as tractor scrapers, employ fluid actuated work elements such as scraper bowls, aprons and ejectors, for example. Each work element has an operator control for controlling movement of the work element. Where there are three work elements, as on a tractor scraper, there are three operator controls. The controls should be spaced and positioned in a logical, functional order, but there is often insufficient space available to accommodate the most logical and functional layout of the controls. Space is also a problem because of numerous conduits connecting the work elements with the controls.
The present invention is directed to overcoming one or more of the problems as set forth above.
According to the present invention, control apparatus is provided for a mechanism which has first, second and third work elements each movable between a first position at which the work element is fully retracted and a second position at which the work element is fully extended. The control apparatus includes a single lever device for controllably moving a selected one of the work elements between the first and second positions while maintaining the other work elements in preselected positions by directing a pressurized fluid in response to movement of the single lever device.